This invention relates to an ambient temperature curable coating composition which forms a durable, weatherable chemical and temperature resistant finish.
The prior art shows coating compositions of acrylic silicone copolymers which are crosslinked by heat or radiation after application to a substrate. Patents showing such compositions are as follows: Sekmakas, U.S. Pat. No. 3,468,836, issued Sept. 23, 1969, Kincheloe et al., U.S. Pat. No. 3,644,566 issued Feb. 22, 1972, Nordstrom et al., U.S. Pat. No. 3,650,813 issued Mar. 21, 1972 and Sekmakas U.S. Pat. No. 3,655,602 issued Apr. 11, 1972.
In the construction or repair of industrial chemical plants and oil refineries, coatings are applied to substrates such as pipes, stacks, tanks, reactors and the like. These coatings must be applied at ambient temperatures, provide protection to the substrate from moisture and weathering before the plant is placed in operation. After the plant is in operation, these coatings are subjected to chemicals and elevated temperature conditions of 100.degree.-200.degree. C. and above the coatings must remain intact and provide protection to the substrates at these elevated temperatures. The aforementioned prior art compositions are inadequate for the above purpose since these compositions must be heated to elevated temperatures or cured by radiation to form a durable coating. This would be impossible or very impractical for new plant construction where the plant would not be operational for a long period of time or in an old plant which generally is painted when the plant is not in operation.
There is a need for a coating composition that does not require curing at an elevated temperature but will cure at ambient temperatures to form a weatherable, durable and chemical resistant finish that will withstand high temperatures which occur during plant and refinery operations.